Over the years there has been extensive development of the technology for moving such small items as books, equipment, and the like. Bags and brief cases come in a wide variety of forms and are adapted for a wide range of purposes. For example, they can be in the form of simple brief cases which can range from soft leather or imitation leather in a rectangular configuration, through to rigid carrying cases made of rigid plastic or leather incorporating rigid elements. Likewise, brief cases made of non-rigid materials are often made rigid with metal strips, metal perimeterial bands which give the brief case a hard edge and soft sides, and the like.
The transport and movement of delicate equipment, such as cameras and the like, present special problems. One classic solution to this problem is the hard plastic case containing a foam plastic shock protector which has a plurality of compartments sculpted into it. The various items to be protected, such as the camera, lens, and the like, are put into compartments which substantially match their shape and size.
In recent years one of the more typical applications for advanced luggage technology has been in connection with the movement of portable computers, such as laptop computers. In this regard a great number of applications have arisen involving structures which provide for the portability of laptop computers.
The earliest structures for containing laptop computers consisted of conventional bags which were simply proportioned and scaled to the job of carrying a laptop computed.
Recognizing the delicate nature of laptop computers, and the liquid crystal screens which they employ, which are perhaps the most delicate and likely to damage part of the computer, bag manufacturers quickly came to realize the special problems involved and began to work on the problem of providing for the safe transport of laptop computers. The first steps to be taken involved the use of shock absorbing materials in the bags.
The materials which they used, which remain in use today, principally comprise foam plastic materials with a wide range of characteristics. Such materials are also used in a wide range of thicknesses, dependent upon the position of the particular shock absorbing member, its characteristics, and other structural features. The problem with such systems is that they will only work for a range of laptop computer sizes which is relatively limited.
More advanced systems have involved the use of shock absorbing pads which are contained within fabric housings. These fabric housings are secured to the inside of the bag by a hook and eye. fabric adhesion system, such as that manufactured by the Velcro Corporation and sold under the trademark Velcro. As may be apparent, the use of Velcro fasteners allows the housings containing the shock absorbers to be moved tube a variety of positions, thus enabling them to accommodate a wide range of sizes of laptop computers with a snug fit, presumably insuring better absorption of shocks due to various types of impact, such as falling, bumping during transport and impacts due to placement on a hard surface such as a table.
In one bag of this type, the sides of the bag are provided with a thin layer of foam material having a thickness on the order of 1 cm. The shock absorber pads are about one inch thick or about 2.5 centimeters in thickness and may be moved to a variety of positions.
In an attempt to address the problem of providing for the transport of laptop computers of different size without the complication of movable shock absorbers, a new type of system has been introduced. In this bag, the four edges of the bag are reinforced with a rigid perimeterial band of rigid plastic or metal which forms a substantially closed loop of rectangular configuration. This closed loop has a thickness substantially equal to the thickness of the bag. The two sides of the bag are provided with a thin layer of foam plastic which serves as a shock absorbing material. The bag is provided with a carrying handle which is secured to one of the sides of the loop. On the opposite side of the loop, an array of rubber shock absorbing bag feet are positioned.
In this system shock absorption is provided by a stretchable or elastic fabric cradle which comprises a rectangular sheet of elastic fabric secured at one end to the rigid band. It is dimensioned to be disposed around the bottom edge of a laptop computer when that computer is being carried around in the bag.
The opposite edge of the rectangular fabric cradle is also secured to the top edge of the rigid band. However, instead of being permanently secured thereto at a fixed position, it is secured by a pair of adjustable straps. The straps are adjustable in their length, thus providing for the accommodation of a range of laptop computer sizes.
In accordance with this technology, if a laptop computer in a bag is dropped, the impact is first felt by the rigid perimeterial band. The impact is transmitted to the laptop computer through the elastic cradle. Because the cradle is elastic, the laptop computer will not be instantly stop, but, instead, will continue to move at substantially its free fall speed, but subject to gradual deceleration due to the force exerted by the elastic cradle as it is being stretched by the displacement of the laptop computer in the downward direction during impact absorption. The rest is that a shock which would normally be experienced by the laptop computer as an impulse, to use the parlance of stochastic linear system analysis, due to the experiencing of a step in the displacement function representing the position of the bag, is smoothed out into a more complex function related to the displacement of the laptop computer after impact and the spring constant for the elastic material of the cradle.